Refrigerating apparatus



Aug. 27, 1940. .1. KARMAZIN REFRIGERATING APPARATUS Original Filed July12,, .1937

2 Sheets-Sheet INVENTOR. rfimv /I ARM/120V.

I 54.4... M HIS ATTO RNEYS.

Aug. 27, 1940. J. KARMAZ IN REFRIGERATING APPARATUS Original Filed July12, 1937 2 Sheets-Sheet 2 "I II INVENTOR. t/B/M/ K1 Mnzml.

BY M 64-4 HIS ATTORNEYS.

Patented Aug. 27, 1940 UNITED STATES PATENT OFFICE REFRIGERATINGAPPARATUS John Karmazin, Grosse lle, Mich., assignor to General MotorsCorporation, Dayton, Ohio, a corporation of Delaware Application July12, 1937, Serial No. 153,077 Renewed January 10, 1940 7 Claims.

" "bondthe members to one another to form an elongated refrigerantrestrictor or combined restrictor and heat exchanger having refrigerantpassages therein and integral fin portions extending from the walls ofthe passages.

A still further object of my invention is to provide an elongatedrefrigerant restrictor or combined restrictor andheat exchanger ofpressed sheet metal construction having a plurality of separated closedrefrigerant passages 25 therein and integral reinforcing meansthroughout the length thereof forming fixed restrictionsto the flowofrefrigerant through one of the passages.

In carrying out the foregoing objects it is a 80 further and morespecific object of my invention to form an elongated small diameteredrefrigerant restrictor of unidirectionally assembled and securedtogether pressed sheet metal members which can be locatedin gaseousrefrigerant 88 headers ordinarily provided between sheet metal shellsforming a refrigerant evaporator.

Further objects-and advantages of the present invention will be apparentfrom the following description, reference being had to the accomopanying drawings, wherein a preferred form of the present invention isclearly shown.

In the drawings:

Fig. 1 is a diagrammatic illustration of a refrigerating system having arefrigerant restric- 48 tor constructed in accordance with my inventioninstalled therein;

Fig. 2 is a perspective view of an evaporator of a refrigerating systemhaving the refrigerant restrictor located in a gaseous refrigerantheader 50 thereof;

Fig. 3 is a perspective view of the evaporator disclosed in Fig. 2 andshowing the refrigerant restrictor located in a different refrigerantheader thereof;

Fig. 4 is a view illustrating diagrammatically a furnace through whichthe restrictors of the present invention are passed for brazing same;Fig. 5 is a enlarged fragmentary sectional view showing unidirectionallynested pressed sheet .metal members assembled together and having 5brazing material disposed internally thereof prior to being placed inthe. furnace disclosed in Fig. 4; Fig. 6 is a view of the members shownin Fig. 5

after having been bonded together to form a re- 10 frigerant restrictorof the present invention;

' Fig. 7 is an enlarged fragmentary sectional view of a combinedrefrigerant restrictor and heat exchanger constructed in accordance withthe present invention;

Fig. 8 is a sectional view through the combined refrigerant restrictorand heat exchanger shown in Fig. 7 and is taken on the line 8-8 thereof;and

Fig.9isaviewsimilartoFig.6andshowinga portion of a restrictorconstructed of pressed sheet metal members of modified form.

Referring to Fig. 1 of the drawings, there is shown a refrigeratingapparatus comprising a motor-compressor unit ill havingan outlet I2 26through which compressed refrigerant is delivered by means of a conduitIt to a condenser It. Refrigerant liquefied in the condenser i6 isdelivered through conduit I! to a heat exchanger, comprising conduit llthermally secured to a 8 conduit 18, whence it passes to the refrigerantflow control device or restrictor, generally represented by thereference character IQ, for delivery by conduit H to the evaporator".Re-

frigerant vaporized in the evaporator 22 is de- 85 livered by means ofthe suction conduit I8 to the inlet 23 of the compressor unit iii. Asuitable thermostat or automatic control device 25 is provided forintermittently operating the motorcompressor unit ill to providesubstantially constant temperatures at the evaporator 22. The systemoperates in the conventional manner to withdraw heat at the evaporatorfrom a food compartment or other object to be cooled and to dissipateheat at the condenser to the room air or other cooling medium.

r In Fig. 1 the refrigerant flow control device or restrictor I9 islocated outside the walls of the evaporator 22. The restrictor I9 may,however, be located between the sheet metal members or shells formingwalls of the evaporator and to illustrate this I have shown in Fig. 2 ofthe drawings the restrictor l9a as being disposed within an enlargedgaseous refrigerant header located at the upper part of one leg of theevaporator 22.

In Fig. 3 I have shown the restrictor l9b as being within an enlargedrefrigerant header located at the bottomof the evaporator 22 and adaptedto discharge liquid refrigerant directly thereinto. The forming of therestrictor l9 into an elongated shape and of small diameter 1naccordance with the present invention permits its location within theevaporator 22 itself as illustrated in Figs. 2 and 3 to thereby serve asa heat exchanger as well as a refrigerant control device.

Referring now to Fig. 5 of the drawings I have shown a plurality ofunidirectionallysuperimposed sheet metal members each having a taperedtubular portion 3| struck or pressed therefrom and teiescoped together.Each sheet metal member also has an integral fin portion 32 extendingoutwardly from the tube part 3| thereof and an end wall portion 33. Instriking the tube portion 3| from a sheet metal blank of predeterminedsize and shape an orifice or small opening 34 is punched from the blankat the. center of the end wall 33. A predetermined number of the pressedsheet metal cup members are stacked one upon another to form anelongated structure of any desired length. A hollow metal end element 35having a tapered surface 36 fitting within the end sheet metal member ofthe stacked structure is adapted to receive the end of the refrigerantconduit 2|. At the opposite end of the assembled structure I place anend sheet metal cup member provided with a relatively large opening 38for the reception of the end of the liquid refrigerant conduit l'|.After assembling a restrictor device of predetermined length asdescribed and as shown in Fig. 5 a copper brazing strip or rod 39 ispassed through the openings 34 of the cup members so as to be dis-'posed within the assembled structure. The assembled structure is then.placed on a conveyor belt ll (see Fig. 4) mounted upon driving pulleysl2 and caused to travel into and through the furnace 43. Heat generatedin any suitable or desirable manner within the furnace l3 melts thecopper brazing strip or rod 39 and causes the copper to flow intocrevices at the joint between the prmsed sheet metal cup members ofthestructure l9 to bond the members together in fluidtight relationship.The restrictor structure I 9 may, if desired, be turned or rotatedduring its travel through the brazing furnace 43 to cause uniform flowof the molten copper or rod 39 therein so as to insure the making ofuniform bonds or fluid-tight joints between the plurality of pressedsheet metal cup members. After the brazed structure l9 has had conduitsl1 and 2| secured thereto as shown; in Fig. 6 of the draw- 7 ings theorifices or small openings 34 formed in the plurality of pressed sheetmetal cup members thereof, provide a passage of small crosssection andrelatively great length therethrough.

In operation of the refrigerating system liquid refrigerant is fed fromthe pipe Il into the restrictor I9 at one end thereof. Since the walls3! of the plurality of pressed sheet metal cup members of the restrictordevice provides a plurality of relatively large chambers throughout thelength of the restrictor any sediment entering same will collect and betrapped in these chambers. Thus the chambers within the restrictor i 9prevent clogging of the'orificcs to insure proper flow of refrigeranttherethrough and to control the passage of refrigerant from the high tothe low pressure side of the refrigerating system.

The chambers within the restrictor l9 also renders the purpose of afilter screen thcreinjunnecessary. Liquid refrigerant under pressure inconduit i! has its pressure reduced to the low pressure prevailing inconduit 2| and evaporator 22 by the great frictional or viscousresistance to the flow of fluid through the plurality of orifices 5,;

in the restrictor, as is well-known in the art.

In Fig. 9 of the drawings I have shown a modified form of refrigerantflow device or restrictor and the pressed sheet metal cup membersthereof have their bottoms 33a bent or formed inwardly as at 45. Theforming of the sheet metal cup members as shown at 45 in Fig. 9 providesa restrictor of increased structural strength over the restrictor l9shown in Fig. 6 to prevent deformation thereof. It is to be understoodthat the pressed sheet metal cup members of my improved restrictor maytake various forms without departing from the principle of theinvention.

Referring now to Fig. 7 of the drawings 1 have k disclosed a unitarycombined restrictor and heat exchanger structure generally representedby the reference character 50 and adapted to be inter posed in thegaseous refrigerant suction conduit i 8 of the refrigerating system andpreferably closely adjacent the evaporator 22. By employing the combinedstructure 50 in a refrigerating system the positioning of therestrictor-s IM and I9b within the walls of the evaporator or thewelding orsoldering of the refrigerant conduits l1 and Min intimatethermal contact with one another to provide a heat exchanger for therefrigerating system is unnecessary. The combined restrictor and heatexchanger 50 comprises a plurality of unidirectionally superimposedsheet metal members each having two tapered tubular portions 5| and 52struck or pressed therefrom. The tubular portion SI of each sheet metalmember is of larger diameter than the tubular portion 52 thereof andthese portions of one sheet metal member are telescoped upon or intosimilar portions of another of the members. Each of the sheet metal,members of the restrictor 50 has an the tubular portion 5| thereof. Theweb part 54 of each sheet metal member of restrictor 50 extending fromand connecting the tubular portions 5| and 52 thereof has a plurality ofopenings 55 punched therein (see Fig. 8). In striking the sheet metalmembers of the restrictor 59 from a blank of predetermined size andshape an orifice to form an elongated structure of any desired r length.A metal plug element 69, having a tapered surface 59 fitting within apart of the tapered wall of tubular'portion II and having anothertapered surface 6| fitting within a part of the tapered wall of tubularportion 52 of the end sheet metal member of restrictor 50, isadapted toreceive an end 'of the gaseous refrigeraiit suction conduit I 8 of therefrigerating system. This element 58 is provided with an opening or aplurality of openings 63 extending entirely therethrough to permit thepassage of gaseous refrigerant from one portion to another portion ofconduit l8 through the device 50 interposed therein. Another opening 8dprovided in element'iiB communicates with the interior of the combinedelement or device 50 and has an end of the refrigerant conduit 28secured therein.

over and receives the tapered wall of tubular portion 5| and has asecond hollowed-out part II which fits over and receives the taperedwall of the tubular portion 52 of the sheet metal mem-- bers of thestructure. This element 68 also has an opening or a plurality ofopenings 12 extending entirely therethrough to permit the passage ofgaseous refrigerant from one portion to another portion of conduit I8through the device 50. Another opening 13 provided in element 68communicates with the interior restricted portion of device 50 and hasan end of the liquid refrigerant conduit l'l secured therein.

By reference to Fig. '7 it will be noted that compressed relatively warmliquid refrigerant flowing from conduit I'l enters the elongated passageextending through the device 50 and formed by the smaller diameteredtubular portion 52 of the sheet metal members thereof. The orifices orsmall openings 56 provide an elongated passage of small cross-sectionand of relatively great length through the device 50. The liquidrefrigerant upon passing through the elongated passage of device 50 hasits pressure reduced to a lower pressure and flows from the device 50through opening 64 and conduit 2| to the evaporator. Gaseous refrigerantflowing from the evaporator to the compressor of the refrigeratingsystem .by way of conduit I8 is directed through the openings 63 inelement 58 at the one end of device 50, through the passage formedbetween the two tubular portions 5| and 52 of the plurality of sheetmetal members of device 50 and through the openings I2 in element 68.The liquid refrigerant flowing towards the evaporator in the use of thedevice 50 is surrounded by refrigerant flowing from the evaporator andin this way the cool gaseous refrigerant gives up its heat to therelatively warm liquid refrigerant to precool same. Therefore the device50 provides an eflicient improved form of heat exchanger for therefrigerating system. It is to be understood that the various sheetmetal members of the combined heat exchanger and restrictor 50 may bebonded together in much the same manner as various parts of therestrictor l9. Prior to heating device 50 copper brazing rods may beinserted in both refrigerant passages thereof to thereby seal thepassages from one another in fluid-tight relationship. The metal members35, 35a, 58 and 68 and the refrigerant pipes communicating therewith maybe bonded to the structure in any suitable or desirable manner.

From the foregoing it will be seen that I have provided an improved flowcontrol'device or an improved combined refrigerant flow control deviceand heat exchanger for a refrigerating system which can be constructedfrom a plurality of unidirectionally nested and secured together sheetmetal integral fin and tube members. It will be seen that the devicesdisclosed while being elongated are of great structural strength due tothe superimposing, telescoping and bonding together of the pressed sheetmetal members. My invention provides structures that can be readilyassembled into various lengths as desired and can be manufactured at lowcost.

While the form of embodiment of the invention as herein disclosed,constitutes a preferred form, it is to be understood that other formsn'iight be adopted, all coming Within the 'scope of the claims whichfollow.

What is claimed is as follows:

1. In a refrigerating system, an element forming a combined heatexchanger and control device for controlling the flow of refrigerantfrom the high pressure side to the low pressure side of the systemcomprising, a plurality of unidirectionally superimposed sheet metalmembers each having a tube portion telescoped into the tube portion ofan adjacent member and secured thereto. to provide a wall of a closedrefrigerant passage extending through the element, each of saidplurality of sheet metal members also having a second integral tubeportion telescoped into the second integral tube portion of an adjacentmember andsecured thereto to provide a wall of a second closedrefrigerant passage extending through the element and surrounding saidfirst named passage, and certain of said sheet metal members having anintegral part thereof extending a predetermined distance into one ofsaid passages to form aplurality of obstructions to the flow ofrefrigerant therethrough.

2. In a refrigerating system, an element forming a combined heatexchanger and control device for controlling the flow of refrigerantfrom the high pressure side to the low pressure side of the systemcomprising, a plurality of unidirectionally superimposed sheet metalmembers each having a tube portion telescoped into the tube portion ofan adjacent member and secured thereto to provide a wall of a closedrefrigerant passage extending through the element, each of saidplurality of sheet metal members also having a second integral tubeportion telescoped into the second integral tube portion of an adjacentmember and secured thereto to provide a wall of a second closedrefrigerant passage extending through the element and surrounding saidfirst named passage, and certain of said sheet metal members having anintegral part thereof extending a predetermined distance into the saidfirst named passage to form a plurality of obstructions to the flow ofrefrigerant therethrough.

3. In a refrigerating system, an element forming a combined heatexchanger and control device for controlling the flow of refrigerantfrom the high pressure side to the low pressure side of the systemcomprising, a plurality of unidirectionally superimposed sheet metalmembers each havinga tube portion telescoped into the tube portion of anadjacent member and secured thereto to provide a wall of a closedrefrigerant passage extending through the element, each of saidplurality of sheet metal members also having a second integral tubeportion telescoped into the second integral tube portion of an adjacentmember and secured thereto to provide a wall of a second closed'refrigerant passage extending through the element and surrounding saidfirst named passage, certain of said sheet metal members having anintegral part thereof extending a predetermined distance into'one ofsaid passages to form a plurality of obstructions to the flow ofrefrigerant therethrough, and certain of said f tionally superimposedsheet metal members each having a tube portion telescoped into the tubeportion of an adjacent member and secured thereto to provide a wall ofa'closed refrigerant passage extending through the element, each of saidplurality of sheet metal members also having a second integral tubeportion telescoped into the second integral tube portion of an adjacentmember and secured thereto to provide a wall of a second closedrefrigerant passage extending hrough the element-and surrounding saidfirst named passage, each of said sheet metal members having an integralpart thereof extending a predetermined distance into said first namedPassage, said integral part of said sheet metal members being disposedin spaced apart relation to one another to form a plurality ofobstructions to the flow of refrigerant through said first namedpassage, and each of said sheet metal members also having an integralfin portion extending outwardly from the wall of said second namedrefrigerant passage. 2

5. In a refrigerating system, an element forming a combined heatexchanger and control device for controlling the flow of refrigerantfrom the high pressure side to the low pressure side,

of the system comprising, a plurality of unidirectionaliy superimposedsheet metal members eachsaid plurality of sheet metal members alsohaving a second integral tube portion telescoped into the secondintegral tube portion of anadjacent member and secured thereto toprovide a wall of a second closed refrigerant passage extending throughthe element and surrounding said first named passage, each of said sheetmetal members having an integral part thereof extending a predetermineddistance into said first named passage, said integral part of said sheetmetal members being disposed in spaced apart relation to one another toform a plurality of obstructions to the flow of refrigerant through saidfirst named passage, each of said sheet metal members also having anintegral fin portion extending outwardly from the wall of said secondnamed refrigerant passage, and the portion of each of said sheet metalmembers connecting the tube portions thereof being perforated to permita substantially non-restricted flow of refrigerant through said secondnamed refrigerant passage.

6. A refrigerating apparatus comprising, an

evaporator, a condenser, and a motor-compressor unit operativelyconnected together by conduits to form a closed refrigerant fluidcirculating system, means interposed in the conduit leading from saidcondenser to said evaporator for dividing said system into a highpressure side and a low pressure side and adapted to control the flow ofrefrigerant fluid therebetween, said means including a. plurality ofunidirectionally superimposed sheet metal members each having a tubeportion telescoped and secured together to provide a wall of a closedpassage adapted to extend therethrough, certain of said sheet metalmembers having an integral part thereof projecting into the passage andprovided with an opening and said integral part of said certain of thesheet' metal members being disposed in spaced apart relation to theintegral part of other of the certo form a closed refrigerant fluidcirculating system, means interposed in the conduit leading from saidcondenser to said evaporator for dividing said system into a highpressure side and a low pressure side and adapted to control the flow ofrefrigerant fluid therebetween, said means in-' cluding a plurality ofunidirectionally superimposed sheet metal members each having a tubeportion telescoped and secured together to provide a wall of a closedpassage adapted to extend' therethrough, certain of said sheet metalmembers having an integral part thereof projecting into the passage andprovided with an opening, said integral part of said certain of thesheet metal members being disposed in spaced apart" relation to theintegral part of other of the certain members with the openingsthereinof such size and character as to form restrictions at a pluralityof points along the passage to the fiow of refrigerant fluidtherethrough, and certain of said sheet metal members having an integralfin portion extending outwardly from the wall of said passage.

- JOHN IN.

